Blue Ribbon Exotic Environments Purple Geode Stone Aquarium Ornament. Geodes are the "box of chocolates" of the rock world - you never know what you're going to get! This amazing replica of a natural wonder will enhance any tank.
A little about geodes: geodes look just like normal rocks on the outside, but contain amazing crystals on the inside! Geodes are formed when rock hardens around a cavity (like a volcaninc gas bubble). Dissolved minerals inside then harden to form beautiful crystals, such as amethyst.